powerpc: wii.dts: Add interrupt-related properties to GPIO node

The Hollywood GPIO controller is connected to the Hollywood PIC (&PIC1)
at IRQs 10 and 11; IRQ 10 for GPIO lines that are configured for access
by the PPC, 11 for GPIO lines that are configured for access by the
ARM926.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/boot/dts/wii.dts

@@ -187,6 +187,11 @@ GPIO: gpio@d8000c0 {
 				"DEBUG0", "DEBUG1", "DEBUG2", "DEBUG3",
 				"DEBUG4", "DEBUG5", "DEBUG6", "DEBUG7";
 
+			interrupt-controller;
+			#interrupt-cells = <2>;
+			interrupts = <10>;
+			interrupt-parent = <&PIC1>;
+
 			/*
 			 * This is commented out while a standard binding
 			 * for i2c over gpio is defined.